Despite significant efforts to educate women to not drink during pregnancy, the incidence of Fetal Alcohol Spectrum Disorders has not declined making it important to obtain understanding of the mechanisms by which prenatal alcohol exposure causes neurodevelopmental damage in order to develop preventative and ameliorative strategies. In this proposal, we will exploit the unique advantages of the well established sheep model to investigate basic mechanisms by which alcohol causes brain injury and to begin exploring protective strategies. We have reported that alcohol causes maternal and fetal acidemia and reductions in maternal glutamine and glutamine-related metabolites. We hypothesize that alcohol mediated acidemia decreases fetal glutamine and glutamine-related metabolites and that this results in, or contributes to, elevations of oxidative stress and brain injury. In Specific Aim 1, we hypothesize that alcohol induces maternal and fetal acidosis that results in altered concentrations of glutamine and its nitrogenous metabolites in the fetus. Experiment 1 tests this hypothesis in chronically instrumented lamb fetuses in response to acute alcohol or acidemia manipulations and will determine if maternal glutamine will prevent the changes in metabolite concentrations. In Specific Aim 2, we hypothesize that prenatal alcohol exposure throughout the 3rd trimester equivalent of human brain development acts by causing acidemia, reductions in fetal glutamine and increases in oxidative stress. Experiment 2a will determine if alcohol or acidemia alters concentrations of glutamine and its metabolites in, and flux between, maternal and fetal compartments and across the fetal brain and if maternal glutamine administration prevents these changes. Experiment 2b will test whether the alcohol mediated decreases in pH and glutamine throughout the third trimester equivalent of human brain development results in increases in oxidative stress and if maternal glutamine is preventative. Specific aim 3 hypothesizes that maternal glutamine administration will prevent the fetal brain injury in response to 3rd trimester equivalent alcohol exposure (Experiment 3 tests this hypotheis). Because alcohol is known to act through more than one mechanism, we predict that glutamine will substantially but not completely prevent brain injury and that these findings will place us in an excellent position to develop a practical, combinatory, nutritional prevention, a stated goal in the NIAAA strategic plan. PUBLIC HEALTH RELEVANCE: The failure of education to significantly reduce the incidence of Fetal Alcohol Syndrome has made it important to obtain understanding of the mechanisms by which prenatal alcohol exposure causes neurodevelopmental damage in order to develop preventative and ameliorative strategies. In this proposal we test several hypotheses that would explain how alcohol causes this damage and will test a nutritional prevention based on the on these hypotheses. This research addresses a stated goal in the National Institute on Alcoholism and Alcohol Abuse strategic plan.